The 300 series stainless steel flat washer has a black oxide finish and meets United States Military Standard MS 15795 specifications. The flat washer provides a bearing surface for fastener load distribution or is used as a spacer between components. The 300 series stainless steel material provides strength and offers good corrosion resistance in many environments. The material may be slightly magnetic. The black oxide finish offers additional corrosion resistance and lubricity.
Washers distribute the load of a fastener across a surface and can also be used as spacers, springs, shims, or locking devices. Several different washer styles fit a variety of application and installation requirements. The most common style is a flat washer. More specialized washers provide additional benefits. A cup washer, for example, helps protect fasteners from electrical currents, while a lock washer offers additional security in an assembled workpiece.